This invention relates to a process for polymerizing polar o-olefinic monomers to "living" polymers and to the "living" polymers produced by such a process.
The technology known as group transfer polymerization is described in U.S. Pat. Nos. 4,417,034--Webster and 4,414,372--Farnham and Sogah, both granted in 1983. The former claims "living" polymers and their preparation from acrylic-type or maleimide monomers using defined organosilicon, -tin, or -germanium initiators and a catalyst which is a source of fluoride, cyanide or azide ions or a suitable Lewis acid. The latter is similar but uses as a co-catalyst a source of bifluoride ions. Both disclose various suitable solvents for the catalyst including acetonitrile used in amounts including 19 moles per mole of catalyst and more, and acetonitrile is used in larger quantities as a general solvent for the polymerization.
By "living" polymer is meant a polymer of the invention which contains at least one active terminal group and is capable of polymerizing further in the presence of monomer(s) and co-catalyst. The words "living" and "livingness" are used herein to quotation marks to distinguish from any biological conotations.
In attempts to use group transfer polymerization to better advantage, it would be desirable to find ways to increase or enhance the duration of the "livingness" of the polymerization. This would involve somehow decreasing the proportion of termination to further polymerization events. This could lead to higher molecular weight, lower polydispersity, and better control and predictability of molecular weight.
Related applications include Ser. Nos. 660,588 and 660,589 filed Oct. 18, 1984, now U.S. Pat. No. 4,581,428; 673,926 filed Nov. 21, 1984; and 676,099 filed Nov. 29, 1984, now abandoned. Also, application Ser. No. 707,193, filed Mar. 1, 1985, now U.S. Pat. No. 4,588,795, which discloses and claims the use of certain types of oxyanion catalyst in group transfer polymerization.
The disclosures of the above-mentioned patents and applications are hereby incorporated by reference.